Variable resistor device provided with a plurality of variable resistors

ABSTRACT

A semifixed, gang and print type variable resistor which is economical and used mainly with a color television set at its reverse side and in which a plurality of variable resistor elements can readily be fitted on a single insulating base plate.

United States Patent [72] Inventors Katsuml Ichikawa;

Helroku Tanaka; Katsuyoshi Onda, all of Osaka, Japan [21 Appl No. 846,905

[22] Filed Aug. 1, 1969 [45] Patented Aug; 10, 1971 [73] Assignee Matsushita Electric Industrial (30., Ltd.

Osaka, Japan [32] Priority Aug. 6, 1968, Aug. 6, 1968, Aug. 6, 1968,

Aug. 6, 1968, Oct. 17, 1968 i 3 3 l Japan and 43/92303 [54] VARIABLE RESISTOR DEVICE PROVIDED WITH A PLURALITY 0F VARIABLE RESISTORS 4Clai1ns, ISDraWiugFigs.

[52] U.S.Cl 338/128, 338/162 [51] lnLCl. H0lc9/02 [50] Field ofSearch 1, 338/118, 128-131, 134, 149, 160, 162, 166, 171

[56] 116166611613 Cited UNITED STATES PATENTS 2,925,575 2/1960 Bal'del'l..m.... 1. 338/166 3,412,360 11/1968 COibUl'l'l 338/162 3,421,133 1/1969 VanBenthuysen 338/128X 3,497,856 2/1970 $611661 338/162 FOREIGN PATENTS 991,774 5/1965 GreatBritain 338/162 Primary Examiner1.ewis H. Myers Assistant Examiner-Gerald P. Tolin Altorney- Stevens, Davis, Miller & Mosher ABSTRACT: A semifixed, gang and print type variable resistor which is economical and used mainly with a color television set at its reverse side and in which a plurality of variable resistor elements can readily be fitted on a single insulating base plate.

I PATENTEDnummsn 3 SHEET 10F 5 INVENTORS KATSUMI ICH IKAWA HEIROKU TANAKA KATSUYOSHI ONDA BY d/ m J ef'r'roumws PATENTED AUG 1 019?:

SHEET 4 UF 5 VARIABLE RESISTOR DEVICE PROVIDED WITH A PLURALITY OF VARIABLE RESISTORS This invention relates to a variable resistor, and more particularly to a semifixed, gang and print type variable resistor which is economical and used mainly with a color television set at its reverse side.

The present invention intends to provide a variable resistor constructed by a combination of simply configured parts so as to reduce the unstableness of the variable resistor shafts such as slipping off or looseness thereof which are inherent in the variable resistor of this type.

According to the present invention there is provided a gang type variable resistor which comprises a flat insulating base plate provided with a plurality of openings, a plurality of variable resistor shafts inserted into the openings formed in the insulating base plate, a caulking plate fitted by caulking on each of the variable resistor shafts, and a plurality of variable resistor elements fitted thereby on the insulating base plate.

Thus, according to the present invention, a plurality of variable resistors may be readily fitted on a single insulating base plate with a result that the slipping off or looseness of the variable resistor shafts may be effectively prevented.

The above and other objects and features of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a front view showing an example of the gang-type variable resistor according to the present invention;

FIG. 2 is a side view of the variable resistor shown in FIG. 1;

FIG. 3 is a rear view of the same resistor;

FIG. 4 is a front view showing the insulating base plate used with the same resistor;

FIG. 5 is a front view of the metal plate used with the same resistor;

FIGS. 6a, 6b and 6c are front, side and sectional view of the caulking plate used with the same resistor;

FIG. 7 is a front view showing another example of the gang type variable resistor according to the present invention;

FIG. 8 is a side view of the variable resistor shown in FIG. 7;

FIG. 9 shows a rear view of the same resistor;

FIG. 10 is a front view showing the insulating base plate used with the variable resistor of FIG. 7;

FIG. 11 is a front view of the metal plate used with the same resistor;

FIG. 12 is a front view showing still another example of the gang type variable resistor according to the present invention;

FIG. 13 is a side view of the resistor shown in FIG. 12;

FIG. 14 is a front view showing the metal plate used with the resistor of FIG. 12;

FIG. 15 is a side view showing still another example of the variable resistor according to the present invention; and

FIG. 16 shows the same resistor in cross section.

Referring now to FIGS. I to 6, there is shown a first example of the present invention which includes a flat insulating base plate 1 formed with a plurality of openings for fitting thereon a plurality of variable resistor shaft skirts 2. A pair of steel sup- 5 porting legs 3 provided to both longitudinal ends of the flat insulating base plate 1 are adapted to mount the base plate 1 on a printed circuit board (not shown). A metal plate 4 provided with a plurality of openings is disposed on one side of the base plate 1 in contact therewith. The metal plate 4 is also provided with projections 5 for limiting the rotation of variable resistor shafts 6 which extend through the opening formed in the insulating base plate 1 and metal plate 4, as clearly shown in FIG. 2. Each of the variable resistor shafts 6 has one of its ends extended beyond the metal plate 4, and at this end of each shaft 6 there is fitted a flanged caulking plate 7 having a hexagonal center portion which is caulked. As shown in FIG. 6, the flange of the caulking plate 7 is an annular ridge formed peripherally around the caulking plate and having a slight height 7 so that the smallest possible contact is accomplished LII between the metal plate 4 and the caulking plate 7 so as to provide smooth rotation of the variable resistor shafts 6. Each caulking plate 7 has a projection 8 formed to extend radially and partially peripherally thereof as shown in FIG. 6a. Numeral 9 denotes terminals of the horseshoe type variable resistor shaft skirts, and numeral 10 denotes center terminals led out of slide members sliding on the horseshoe type variable resistor elements.

The assembly and operation of the above-described variable resistor will now be described.

A plurality of horseshoe type variable resistor elements, each having two terminals connected to both ends thereof, are fitted on one side of the insulating plate 1. The center terminals 10 are rivetted on the other side of the insulating base plate I at the positions between every two terminals 9. The

center terminals are electrically connected with the slide members (not shown) which are respectively fitted to the resistor shafts 6 in a conventional manner so as to slide on the horseshoe type resistor elements in accordance as rotate the resistor shafts. Thus the horseshoe type variable resistor element, the slide member, the center terminal and two terminals constitute an electric circuit for providing a resistance, whose resistance value is changed in accordance with the rotation of said resistor shaft, between, for example, said center' terminal and one of the two terminals in a conventional manner. Subsequently the metal plate 4 is fitted on the other side of the insulating plate 1. The variable resistor shafts 6 are inserted into the openings formed on the insulating plate 1 and metal plate 4 as extending their ends to the opposite side. Each of the resistor shafts 6 is restricted from its rightwards displacement in FIG. 2 by a well-known method such as, for example, a step provided on the shaft or the shaft skirt to be engaged with the insulating plate 1. The caulking plate 7 is fitted to the extending end of the resistor shaft with the annular ridge thereof in contact with the metal 4. Then the hexagonal center portion of the caulking plate 7 is caulked so as to prevent the variable resistor shaft 6 from slipping out of the opening, but permit the shaft to be rotated in the opening.

Finally the supporting legs 3 are fitted to the insulating base plate 1 at its opposite edges, and thus the assemblage is completed.

In the variable resistor thus assembled, if each variable resistor shaft 6 is rotated, the caulking plate 7 which is securely connected to the variable resistor shaft skirt by caulking will also be rotated until the projection 8 of the caulking plate 7 bears against the projection 5 of the metal plate 4. In this way the rotation of the caulking plate 7 and accordingly of the variable resistor shaft 6 may be limited.

As has been disclosed above, the gang type variable resistor of the present invention employs a flat insulating base plate formed with a plurality of openings into which a plurality of variable resistor shafts are inserted, and each of the variable resistor shafts has a caulking plate fitted thereon by caulking. Thus, according to the present invention, a plurality of variable resistor elements can be effectively fitted to a single insulating base plate simply by caulking the caulking plates. Moreover, the caulking plates prevent the variable resistor shafts from slipping out of the insulating plate as well as from loosening, and the assembly thus provided is very excellent as a gang type variable resistor. I

Furthermore, with the gang type variable resistor according to the present invention, the limit of the rotation of a plurality of variable resistor shafts is accomplished by a single metal plate having a plurality of projections which cooperate with the projections formed in the caulking plate. The use of such a single metal plate as means for limiting the rotation of the variable resistor shafts leads to a greater ease in the manufacture and assemblage than in the case of conventional variable resistors which required a similar limit means for each variable resistor element. In addition, the single metal plate attached to the insulating base plate serves to provide a greater mechanical strength of the final assembly.

Description will now be made of a second example of the gang type variable resistor according to the present invention.

Referring to FIGS. 7 to 11 in which like parts are indicated by like numerals used in the above-described first embodiment, the parts in use are substantially similar to those shown in FIGS. 1 to 6, but arrangement of the parts issomewhat different from the first example. In this embodiment, the variable resistor shaft skirt 2 are disposed on the'side of the insulating plate 1 opposite to that side on which the variable resistor elements of the first embodiment are disposed. Also, the metal plate 4 and caulkingplates 7 are disposed on the side of the insulating base plate 1 different from that side on which the plates 4 and 70f the first embodiment are disposed. Accordingly, the location of the other parts except supporting legs 3' are also opposite to that in the case of the previous embodiment. The supporting leg s3 for mounting the entire ass'embly to a mounting plate (not shown) are formed integrally with the metal plate 4, in contradistinction to the supporting legs 3 of the first embodiment which are provided to the insulating plate I. The gang type variable resistor according to this embodiment achieves the same effect and advantages as the first embodiment.

. Turning to, FIGS. 12 to 14, there is shown a third example of the gang type variable resistor according to the present invention. It comprises an insulating base plate 11, a plurality of variable resistor elements lZ, a plate 13 for mounting a slide member thereon, a plurality of shafts 14, a metal plate 16 formed with a plurality of stopper projections 15, and a plurality of plates 17 for limiting the rotation of shafts 14 formed with projections 18 which are adapted to bear against the stopper projections of the metal plate 16 so that the rotation of the shafts 14 is limited. Center terminals 19 are provided integrally with the metal plate 16 to provide external terrninals'and these terminals 19 are electrically connected with slidable terminals of slide members 20 by means of rivets 2l,'the slidemembers 20 being provided on the plate 13. On the insulating base plate 11 there are provided external terminals 22 and 23 which lead out from both ends of each resistor element 12. v

FIGS. 15 and 16 show a fourth example of the present invention. in this embodiment, use is made of an insulating plate 24 formed of Bakelite or like material and a plurality of armate resistor elements 25 attached to one side of the insulating plate24. A rotary shaft 26 formed of synthetic resin having resiliency is provided for each of the resistor elements 25, and it has a stopper 27 of an enlarged diameter formed at one end thereof where there is formed an axial slit 28. A cover 29 also formed of synthetic resin is provided to protect the resistor element 25 and a slide member 30 which is securely connected to the cover 29.

The rotary shaft 26 extends through the cover 29 and the stopper 27 formed at one end of the shaft 26 prevents the cover 29 from clipping off the shaft.

ln assembling the above-described variable resistor, an opening having a diameter slightly greater than that of the rotary shaft 26 is fonned at a predetermined point on the insulating plate 24 so that resistor elements 25 are disopposed on the plate 24 in such a manner as to surround the opening. The rotary shaft 26 is inserted into the insulating base plate 24 in the direction from right to left as viewed in FIGS. 15 and 16, until the forward end of the stopper 27 bears against the periphery of the through aperture formed centrally of the cover 29 having its slide member 30 facing the insulating plate 24. Thereupon, if an axial force is applied to the rotary shaft 26, the stopper 27 of the rotary shaft 26 yields to the inner wall of the through aperture in the cover 29 because of the resiliency provided by the slit 28 formed at the end of the shaft 26, whereby the stopper 27 of the rotary shaft 26 passes through the aperture of the cover 29. When the stopper 27 has thus passed through the aperture of the cover 29, it expands again by the resiliency provided by the slit 28 and recovers its original diameter, and thus the stopper 27 now restrains the cover 29 and prevents it from slipping off the rotary shaft 26 because of the resiliency of the shaft 26 as well as of the greater diameter of the stopper 27 than that of the rotary shaft. The connection thus accomplished between the rota shaft 26 and the cover 29 is sufficient to overcome any axial orce applied to the shaft 26 or the cover 29.

The stopper 27 may preferably be tapered, as shown so as to facilitate the insertion ofthe rotary shaft 26 into the cover 39.

From the foregoing description it will be appreciated that the variable resistor according to this embodiment is characterized by the provision of a slit formed axially of the rotary shaft at one of its ends, and an integral stopper having a greater diameter than that of the rotary shaft formed at the same end of the shaft, so that the end of the rotary shaft having the stopper can pass through the through aperture of the cover. With this arrangement, an axial force applied to either the rotary shaft or the cover with the stopper of the shaft bearing against the through aperture of the cover will cause the slit at the end of the shaft to narrow so as to allow the stopper to pass through the aperture of the cover. When the stopper has passed through the aperture, the slit of the shaft recovers its original position because of the resiliency provided by the material of the rotary shaft itself, whereby the cover can no longer slip off the shaft. The cover is pressed against the stopper by the resilient slide member so that there may be maintained a predetermined contact pressure between the slide member and the resistor elements.

We claim:

1. A variable resistor device including a plurality of variable resistors mounted at a plurality of openings on a lamination of a flat insulating base plate and a metal plate, each of said variable resistors comprising a resistor shaft rotatably inserted into a respective one of said openings and having a step in contact with said base plate;

an electric circuit for providing a resistor whose resistance value is changed in accordance with rotation of said resistor shaft, said circuit including a horseshoe type resistor element provided on said insulating base plate, a center terminal connected with a slide member which is fitted to'said resistor shaft and slidable on said resistor element, and two terminals connected to both ends of said resistor element; and a caulking plate secured to said resistor shaft in contact with said metal plate and having a projection engageable with a projection provided on said metal plate for limiting the rotation of said resistor shaft.

2. A variable resistor device according to claim 1 wherein said metal plate is integrally provided with a pair of supporting legs which are adapted to mount said resistor device on another member.

3. A variable resistor device according to claim 1, wherein said metal plate is separated into a plurality of subplates, each including said opening for insertion of said resistor shaft and said projection.

4. A variable resistor device including a plurality of variable resistors mounted at a plurality of openings on a flat insulating base plate, each of said variable resistors comprising a resistor shaft made of a resilient material and having a step in contact with said base plate, an elongated portion of said shaft extending into said opening and having an enlarged end, and a slit axially formed on the end of said elongated portion sufficient to make said enlarged end deformable; a cover having an opening and made of a resilient material and mounted on said elongated portion between said base plate and said enlarged end, said shaft extending through said cover opening, said enlarged end of said shaft being inserted through said cover opening by resiliently deforming said enlarged end; and an electric circuit for providing a resistor whose resistance value is changed in accordance with rotation of said resistor shaft. 

1. A variable resistor device including a plurality of variable resistors mounted at a plurality of openings on a lamination of a flat insulating base plate and a metal plate, each of said variable resistors comprising a resistor shaft rotatably inserted into a respective one of said openings and having a step in contact with said base plate; an electric circuit for providing a resistor whose resistance value is changed in accordance with rotation of said resistor shaft, said circuit including a horseshoe type resistor element provided on said insulating base plate, a center terminal connected with a slide member which is fitted to said resistor shaft and slidable on said resistor element, and two terminals connected to both ends of sAid resistor element; and a caulking plate secured to said resistor shaft in contact with said metal plate and having a projection engageable with a projection provided on said metal plate for limiting the rotation of said resistor shaft.
 2. A variable resistor device according to claim 1 wherein said metal plate is integrally provided with a pair of supporting legs which are adapted to mount said resistor device on another member.
 3. A variable resistor device according to claim 1, wherein said metal plate is separated into a plurality of subplates, each including said opening for insertion of said resistor shaft and said projection.
 4. A variable resistor device including a plurality of variable resistors mounted at a plurality of openings on a flat insulating base plate, each of said variable resistors comprising a resistor shaft made of a resilient material and having a step in contact with said base plate, an elongated portion of said shaft extending into said opening and having an enlarged end, and a slit axially formed on the end of said elongated portion sufficient to make said enlarged end deformable; a cover having an opening and made of a resilient material and mounted on said elongated portion between said base plate and said enlarged end, said shaft extending through said cover opening, said enlarged end of said shaft being inserted through said cover opening by resiliently deforming said enlarged end; and an electric circuit for providing a resistor whose resistance value is changed in accordance with rotation of said resistor shaft. 